In the prior art, various tools have been developed for machining circular grooves in a metal workpiece. The prior art face grooving tools include an elongated shank for holding a replaceable cutting insert which projects outwardly from one end of the shank. The prior art tools often include a support blade, which projects outwardly from the shank and acts as a brace for the cutting insert. The earlier prior art support blades were generally rectangular in configuration, having a V-shaped support groove adapted to receive a cutting insert having a V-shaped trailing surface opposed to a planar leading cutting surface. The cutting edge of the insert projects axially outwardly beyond the support blade such that during a machining operation, wherein the workpiece is rotated relative to the tool, a circular groove could be machined having a depth corresponding to the amount which the insert projects beyond the support blade. Due to the extreme cutting forces bearing on the insert during a machining operation, the amount which the insert can project beyond the blade is limited, since the likelihood of insert fracture increases when a large portion of the insert is left unsupported. Thus the prior art rectangular support blades, which are required to prevent insert fracture, limited the depth of the groove which could be machined.
In order to obviate this shortcoming, support blades were developed having a tapered, arcuate configuration, having a maximum width less than the width of the insert, and a curvature corresponding to the curvature of the groove to be machined. Due to this modified configuration, during a machining operation, the support blade follows the insert and is received in the groove machined thereby.
While the prior art arcuate tapered blades permitted the depth of the grooves to be increased for certain applications the blades failed to provide as much support for the insert as the rectangular blades. More particularly, in a circular cutting operation, the highest forces bearing on the insert occur adjacent its radially outermost cutting edge. The tapered curved support blades provided insufficient mass behind the insert to enable machining under heavy load conditions. Therefore, it would be desirable to provide a face grooving tool with an improved support blade configuration which is adapted to receive a cutting insert and provide sufficient support thereto, particularly adjacent the radially outermost cutting edge thereof, thereby preventing blade failure.
Accordingly, it is an object of the subject invention to provide a new and improved face grooving tool for machining circular grooves in a workpiece including a support blade having a configuration which provides increased support for the insert.
It is another object of the subject invention to provide a new and improved face grooving tool having an arcuate support blade enabling the machining of grooves of increased depths.
It is a further object of the subject invention to provide a face grooving tool having a support blade with the leading surface thereof including an offset, V-groove configuration, which provides increased support for the radially outermost portion of the cutting insert thereby reducing the likelihood of blade failure.
It is still another object of the subject invention to provide a face grooving tool having an arcuate support blade of constant width to provide increased support to the insert.
It is still a further object of the subject invention to provide a face grooving tool having a unique clamping means which includes a bearing arm with a relieved configuration enabling the reach out over the insert to be increased thereby increasing the stability of the tool.